JP2022059884A - Hybrid vehicle - Google Patents

Abstract

To enable regeneration of power when shifting to a deceleration operation by cooling a motor depending on an operation state.SOLUTION: A hybrid vehicle includes: an engine 12 for transmitting drive force to a first drive shaft 28; a motor 13 for transmitting drive force to a second drive shaft 18; a clutch 14 disposed between the motor 13 and the second drive shaft 18; temperature information obtainment means 15 for obtaining information of a temperature of the motor 13; clutch control means 51 for disengaging the clutch 14 when a temperature of the motor 13 reaches or exceeds a given temperature and engaging the clutch 14 when a vehicle 10 is decelerating; cooling means 40 for cooling the motor 13; and cooling control means 52 for adjusting performance of the cooling means 40 cooling the motor 13 between a first state and a second state that is lower cooling performance than in the first state. Further, the cooling control means 52 sets the cooling performance at a cooling limited state being limited than in the first state while the clutch 14 is disengaged and controls the cooling limited state closer to the first state as the temperature of the motor 13 rises.SELECTED DRAWING: Figure 1

Description

The present invention relates to a hybrid vehicle.

In a vehicle that travels by the driving force of an electric motor (motor) such as a hybrid vehicle, a clutch is placed between the electric motor and the wheels, and by connecting the clutch, the rotational force of the electric motor is transmitted to the wheels to transfer the vehicle. At the same time as driving, depending on the operating condition, the rotational force of the wheels is transmitted to the motor to recover the regenerative energy. When the vehicle speed reaches the maximum rotation speed of the motor or the temperature of the motor reaches a predetermined upper limit temperature, the clutch is disengaged to prevent an excessive load from acting on the motor. There is.

In this type of motor, it is necessary to perform appropriate cooling according to the operating condition in order to maintain the state in which the performance can always be exhibited. For example, in Patent Document 1, as a cooling device for a motor provided with a coil on either the stator or the rotor and a permanent magnet on the other, a first branch passage for passing a refrigerant to the coil side of the motor and a permanent magnet side. It is possible to selectively supply to the second branch passage leading to. Then, the discharge amount of the refrigerant from the pump is controlled based on the total calorific value of the motor, and the flow rate distribution control of the refrigerant is performed based on the calorific value of each of the coil side and the permanent magnet side. Further, in Patent Document 2, a first flow path for supplying a cooling medium from a pump to a stator, a second flow path for supplying a refrigerant from a pump to a rotor, and a flow rate and a second flow rate of the cooling medium of the first flow path. A valve for adjusting the flow rate of the refrigerant is provided, and the cooling state of the stator and the cooling state of the rotor are controlled by the valve.

Further, Patent Document 3 describes a stator-side cooling passage for cooling the stator, a rotor-side cooling passage for cooling the rotor, and a distribution means for distributing the refrigerant to the stator-side cooling passage and the rotor-side cooling passage at an arbitrary flow rate ratio. A cooling device equipped with is described. The distribution means changes the flow rate ratio between the stator side cooling passage and the rotor side cooling passage according to the rotation speed of the rotor, and further increases the flow rate ratio to the rotor side cooling passage according to the increase in the rotation speed of the rotor. I have to.

Japanese Unexamined Patent Publication No. 2014-110705 International release WO2017 / 072874 Japanese Unexamined Patent Publication No. 2003-102147

In the above Patent Documents 1 to 3, the refrigerant passages for cooling the electric motor are divided into two systems, a cooling path on the shaft side including the rotor and a cooling path on the stator side. The cooling path on the shaft side tends to be locally cooled when the rotation of the shaft of the motor is stopped, but there is an advantage that the refrigerant can be sprayed to the entire motor if the shaft is rotating. Therefore, if the cooling path on the shaft side is used when the shaft rotates, it is possible to cool the entire motor in a nearly uniform manner. On the other hand, the cooling path on the stator side has a structure that cools the motor by discharging oil from the upper part of the fixed stator to the inside. Therefore, when only the cooling path on the stator side is used, the cooling tends to be limited to local cooling.

By the way, in this type of hybrid vehicle, in the current control, when the vehicle is stopped or the clutch between the motor and the drive wheel is disengaged, only the cooling path on the stator side is used to cool the motor. The power consumption is suppressed. That is, in this state, the cooling performance of the electric motor is relatively low.

Here, if a vehicle in a clutch disengaged state shifts to deceleration operation, there is a request to immediately start recovery of regenerative power using an electric motor. However, if the temperature of the motor is higher than the threshold value, the clutch is forcibly disengaged, and there is a problem that regeneration cannot be performed until the temperature drops. Therefore, the energy of deceleration is wasted until the start of regeneration.

Therefore, an object of the present invention is to appropriately cool the electric motor according to the operating state so that the electric power can be regenerated when the deceleration operation is started.

In order to solve the above problems, the present invention relates to an engine that transmits a driving force to a first drive shaft, an electric motor that transmits a driving force to a second drive shaft, and between the electric motor and the second drive shaft. When the temperature of the motor exceeds a predetermined value, the clutch is disengaged, and when the vehicle is decelerated, the clutch is disengaged. The clutch control means to be connected, the cooling means for cooling the electric motor, and the cooling performance of the cooling means to the electric motor between the first state and the second state in which the cooling performance is lower than that of the first state. The cooling control means includes a cooling control means for adjusting, and the cooling control means sets the cooling performance to a cooling limited state in which the cooling performance is restricted from the first state while the clutch is disengaged, and sets the cooling limited state to the temperature of the motor. A hybrid vehicle that is controlled so that the higher the value is, the closer it is to the first state is adopted.

Here, a battery for supplying electric power to the electric motor is provided, and the cooling control means adopts a configuration in which the cooling limiting state is controlled to be closer to the first state as the remaining capacity of the electric power of the battery is higher. be able to.

In each of these embodiments, an electric motor control means for controlling the operation of the electric motor is provided, and the electric motor control means controls so that the higher the temperature of the electric motor during disengagement of the clutch, the higher the rotation speed of the electric motor. The configuration can be adopted.

Further, in each of these embodiments, the cooling means includes a first cooling path for cooling a member on the rotating side of the electric motor, a second cooling path for cooling a member on the fixed side of the electric motor, and the first cooling path. And a refrigerant supply adjusting means for adjusting the ratio of the refrigerant supplied to the second cooling passage can be adopted.

At this time, in the first temperature range including the predetermined value, the cooling means supplies the refrigerant to the first cooling path and the second cooling path to rotate the electric motor, and from the lower limit of the first temperature range. In the second temperature range set to a lower temperature range, the refrigerant is supplied to the first cooling path and the second cooling path is cut off to rotate the electric motor, so that the temperature is lower than the lower limit of the second cooling path. In the third temperature range set in the range, a configuration can be adopted in which the first cooling path is shut off and the refrigerant is supplied to the second cooling path to stop the electric motor.

According to the present invention, the electric motor can be appropriately cooled according to the operating state to cope with the regeneration of electric power when the deceleration operation is started.

It is a schematic diagram which shows an example of the hybrid vehicle which concerns on this invention. It is a graph which shows the temperature of a motor and the control of a clutch. It is a schematic diagram which shows the cooling means of an electric motor. It is a graph which shows the control of this invention. It is a figure which shows the control of this invention. It is a figure which shows the control of this invention. It is a flowchart which shows the control of this invention.

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a hybrid vehicle 10 (hereinafter, simply referred to as a vehicle 10) equipped with a vehicle control device according to an embodiment of the present invention. In the vehicle 10, the front wheels (front wheels) 11a are driven by the driving force of the engine 12, and the rear wheels (rear wheels) 11b can be driven by the assisting force of the electric motor 13 (hereinafter referred to as the main motor 13). It is a four-wheel drive mild hybrid vehicle. The vehicle control device mounted on the vehicle 10 is for efficiently recovering the regenerative energy by the main motor 13, and includes the main motor 13, the clutch 14 (hereinafter referred to as the main clutch 14), and the main motor 13. The main components are the temperature information acquisition means 15, the vehicle speed sensor 16, the electronic control unit 50, and the like for acquiring the temperature information of the above. In this embodiment, the temperature sensor 15 is adopted as the temperature information acquisition means 15, but a temperature information acquisition means, a temperature information estimation means, and the like having other forms other than the sensor may be adopted.

The main motor 13 is attached to the rear wheel side axle 18 so as to transmit the driving force to the second drive shaft (hereinafter referred to as the rear wheel side axle) 18 leading to the rear wheel 11b. The main motor 13 applies a rotational force to the rear wheels 11b during power running to assist the driving force of the engine 12. This assist force is transmitted to the rear wheel side axle 18 via the main clutch 14 and the rear wheel side differential 19. Further, the main motor 13 recovers regenerative energy (hereinafter referred to as regenerative power) from the rotational force of the rear wheels 11b during braking. Since the main motor 13 is directly connected to the rear wheel side axle 18 via a gear having a small transmission loss, high regenerative efficiency can be obtained.

The main clutch 14 is arranged between the motor 13 and the rear wheel side axle 18. The main clutch 14 has a connection state in which rotational force can be transmitted between the main motor 13 and the rear wheel 11b via the rear wheel side differential 19 and the rear wheel side axle 18, and a cutoff state in which this transmission is cut off. It has a function to switch between. The main clutch 14 is normally connected. The rear wheel side differential 19 has a function of distributing the drive assist force from the main motor 13 to the left and right rear wheels 11b in response to the rotational resistance of the left and right rear wheels 11b.

When the main clutch 14 is connected, the drive assist force is transmitted from the main motor 13 to the rear wheels 11b during power running, and the rotational force of the rear wheels 11b is transmitted to the main motor 13 during braking. Regenerative power is recovered. This regenerative power is charged in the battery 20 mounted on the vehicle 10. When the main clutch 14 is disengaged, the main motor 13 and the rear wheels 11b are disconnected, so that the regenerative power cannot be recovered by the main motor 13 during braking.

The battery 20 is provided with a charge amount sensor 21 that detects the charge amount. Information on the remaining capacity (remaining charge amount) of the battery 20 detected by the charge amount sensor 21 is sent to the electronic control unit 50.

The temperature sensor 15 is attached to the casing 13c or the like of the main motor 13, and the temperature of the casing 13c or the stator 13b immediately inside the casing 13c is adopted as a representative value of the temperature of the main motor 13. However, as the temperature sensor 15, it is also possible to acquire another temperature as a representative value of the temperature of the main motor 13, such as the temperature of the lubricating oil flowing in the vicinity of another part of the main motor 13, for example, the temperature of the main motor 13. can. The temperature information of the main motor 13 detected by the temperature sensor 15 is sent to the electronic control unit 50.

The vehicle speed sensor 16 is provided on an axle or the like and has a function of detecting the speed of the vehicle 10. The vehicle speed information detected by the vehicle speed sensor 16 is also sent to the electronic control unit 50. The position of the vehicle speed sensor 16 shown in FIG. 1 is an example, and the mounting position thereof can be changed as appropriate.

The driving force of the engine 12 is a first drive shaft (hereinafter referred to as a front wheel side axle) that leads to the front wheel 11a via a torque converter 24, a continuously variable transmission 25, an auxiliary clutch 26, and a front wheel side differential 27. It is transmitted to (referred to as) 28. The torque converter 24 has a function of transmitting the driving force of the engine 12 to the continuously variable transmission 25. The auxiliary clutch 26 has a function of switching between a connected state in which the driving force can be transmitted between the engine 12 and the front wheel 11a and a disconnected state in which the transmission is cut off. The front wheel side differential 27 has a function of distributing the driving force from the engine 12 to the left and right front wheels 11a in response to the rotational resistance of the left and right front wheels 11a.

Further, the engine 12 is provided with an auxiliary motor (hereinafter referred to as an auxiliary motor) 29. The auxiliary motor 29 is connected to the crankshaft 31 of the engine 12 by a belt 30, and is mainly used for starting the engine 12. Also, by connecting the auxiliary clutch 26, the regenerative power is recovered during braking. It is also possible. The auxiliary motor 29 is normally rotated by the crankshaft 31 while the engine 12 is operating.

The main motor 13 is an electric motor in which a coil is provided on one of a fixed-side member and a rotating-side member, and a permanent magnet is provided on the other, and an output shaft provided on the rotating-side member is rotated around an axis by a driving force. It exerts the function of. Further, when the rotation from the axle side is input to the output shaft, the regenerated electric power is generated, and the function of the generator for charging the regenerated electric power to the battery 20 is exhibited. By regenerating the electric power in the main motor 13 in addition to the auxiliary motor 29 attached to the engine 12, the deceleration energy can be recovered to the maximum as the regenerative electric power. As shown in FIG. 3, the configuration of the main motor 13 of this embodiment is such that the shaft 13a as an output shaft inserted in the casing 13c, the rotor 13d rotating around the shaft together with the shaft 13a, and the outer periphery of the rotor 13d. It is provided with the provided stator 13b and the like. The shaft 13a and the rotor 13d are members on the rotating side, and the casing 13c and the stator 13b are members on the fixed side.

The main motor 13 is provided with cooling means 40. The cooling means 40 has a function of suppressing the temperature rise or lowering the temperature by cooling each part of the main motor 13. As shown in FIGS. 1 and 3, the cooling means 40 has a cooling passage 42 through which a cooling medium (hereinafter referred to as a refrigerant) is passed in order to cool each member constituting the main motor 13. Generally, a fluid, particularly a liquid such as water or oil, is used as the refrigerant. Refrigerant is supplied to the cooling passage 42 by the pump 41. The pump 41 is driven by electric power from the battery 20.

The cooling passage 42 includes a first cooling passage 42a provided on a member on the rotating side composed of a rotor 13d, a shaft 13a, and the like, a casing 13c, a stator 13b, and the like between the pump 41 that sends out the refrigerant and the main motor 13. It has two systems of a second cooling passage 42b provided in the member on the fixed side to be configured. Further, the cooling path 42 has a return path 42c between the main motor 13 and the pump 41. The first cooling passage 42a has an axial passage 42d that opens at the shaft end of the shaft 13a and extends in the axial direction inside the shaft, and a radial passage that branches from the axial passage 42d and opens to the peripheral surface of the shaft 13a. It has a radial passage 42e and the like. Further, the first cooling passage 42a may have an appropriate passage for a refrigerant on the rotor 13d side as appropriate. The refrigerant cools the shaft 13a through the axial passage 42d and the radial passage 42e, and is discharged in the outer diameter direction from the opening on the peripheral surface of the shaft 13a to cool the rotor 13d. Therefore, if the output shaft of the main motor 13 is rotated, the refrigerant is widely dispersed and the entire main motor 13 can be efficiently cooled. The second cooling passage 42b leads into the casing 13c through the through hole 42f provided in the casing 13c at the upper part of the stator 13b. Therefore, the refrigerant flows down from the upper part of the stator 13b into the casing 13c to mainly cool the stator 13b.

Since the refrigerant supply adjusting means 43 is provided at the branch point between the first cooling passage 42a and the second cooling passage 42b, the ratio of the refrigerant supplied to the first cooling passage 42a and the second cooling passage 42b is adjusted. can do. For example, the ratio of the flow rates of the refrigerant supplied to the first cooling passage 42a and the second cooling passage 42b can be set to an arbitrary value such as 0: 100, 25:75, 50:50, 75:25, 100: 0. Can be set. In this embodiment, a three-way valve is adopted as the refrigerant supply adjusting means 43, but the first cooling passage 42a on the downstream side of the branch point and the second cooling passage 42b on the downstream side of the branch point are respectively used. A flow rate adjusting valve capable of adjusting the opening degree of the valve body may be provided.

Although the details are not shown, the auxiliary motor 29 can have the same configuration as the main motor 13, and the cooling means also has a configuration for circulating the refrigerant in the cooling path as in the main motor 13. Can be done.

The vehicle 10 is provided with a brake pedal 22 and an accelerator pedal 32 operated by the driver. The brake pedal 22 is provided with a brake sensor 23 that detects the depression force of the brake pedal 22 by the driver. Further, the accelerator pedal 32 is provided with an accelerator position sensor 33 that detects the amount of depression of the accelerator pedal 32 by the driver. The brake information detected by the brake sensor 23 and the accelerator information detected by the accelerator position sensor 33 are sent to the electronic control unit 50.

The electronic control unit 50 includes a clutch control means 51 that controls the connection and disconnection of the main clutch 14 and the sub-clutch 26, a cooling control means 52 that controls the cooling means 40, and an electric motor control that controls the main motor 13 and the sub-motor 29. The means 53, the engine 12, and other control means 54 for controlling the vehicle 10 in general are provided.

Regarding the main clutch 14, the clutch control means 51 switches the main clutch 14 from the connected state to the disengaged state when the temperature of the electric motor 13 becomes equal to or higher than a preset threshold value (first temperature threshold value). Further, when the temperature of the electric motor 13 falls below a preset threshold value (second temperature threshold value), the main clutch 14 is switched from the disengaged state to the connected state. The first temperature threshold value and the second temperature threshold value may be set uniformly regardless of the operating conditions, but they can also be set so as to change according to the vehicle speed at that time. Further, if the hunting in which the main clutch 14 repeatedly turns on and off can be avoided in a short time, the first temperature threshold value and the second temperature threshold value can be set to the same temperature. FIG. 2 shows control of engagement / disengagement of the main clutch 14 based on the first temperature threshold value and the second temperature threshold value. The section X in the figure is a period during which the main clutch 14 is disengaged based on the temperature of the main motor 13. Further, when the vehicle 10 is in the decelerated state, the clutch control means 51 puts the main clutch 14 in the connected state in order to acquire the regenerative power. It should be noted that the regeneration of electric power can also be performed by the auxiliary motor 29.

The electric motor control means 53 controls the outputs of the main motor 13 and the sub motor 29 in cooperation with the operations of the main clutch 14 and the sub clutch 26 by the clutch control means 51. Further, when the electric power is regenerated, the acquired regenerative electric power is supplied to the battery 20 to be charged. The cooling control means 52 adjusts the cooling performance of the main motor 13 by the cooling means 40 between the first state in which the cooling performance is exhibited and the second state in which the cooling performance is lower than the first state. When the auxiliary motor 29 is provided with the cooling means, the cooling control means 52 can also adjust the cooling performance of the auxiliary motor 29.

An example of the control of the present invention will be described with reference to FIGS. 4 to 7. As shown on the left side in FIG. 4, when the vehicle speed increases due to the driver's acceleration request, the temperature of the main motor 13 also increases accordingly. When the temperature of the main motor 13 (“the temperature of the electric motor” in the figure) becomes equal to or higher than the first temperature threshold value a, the main clutch 14 is switched to the disengaged state. As shown in FIG. 2, the first temperature threshold value a is a temperature at which the main clutch 14 is switched from the connected state to the disconnected state when the temperature of the main motor 13 becomes higher than that. Here, the drive of the main motor 13 is stopped, and the subsequent rotation speed (“rotation speed of the electric motor” in the figure) changes at the rotation speed of idling due to inertia (“idle rotation speed” in the figure). The drive of the main motor 13 is stopped, and the temperature of the main motor 13 drops.

Here, in order from the highest temperature, the first temperature threshold a (for example, a = 120 ° C.), the second temperature threshold b (for example, b = 110 ° C.), the third temperature threshold c (for example, c = 105 ° C.), and the first. 4 temperature threshold d (for example, d = 100 ° C.) is defined, the first temperature threshold a or more is the temperature range A, the second temperature threshold b or more and less than the first temperature threshold a is the temperature range B, and the third temperature threshold. C or more and less than the second temperature threshold b is defined as the temperature range C, and the fourth temperature threshold d or more and less than the third temperature threshold c is defined as the temperature range D. That is, the temperature range B is set to a temperature range lower than the lower limit of the temperature range A, the temperature range C is set to a temperature range lower than the lower limit of the temperature range B, and the temperature range D is lower than the lower limit of the temperature range C. It is set to a temperature range, and the temperature range E is set to a temperature range lower than the lower limit of the temperature range D.

Here, when the main clutch 14 is disengaged, cooling by the cooling means 40 starts under the cooling condition 1. The cooling condition 1 is a cooling method in the temperature ranges A and B (see also FIG. 4 for the temperature ranges A and B) shown at the top of the chart (map) of FIG. Under the cooling condition 1, since the first cooling path discharge flag 1 is set, cooling by the first cooling path 42a is used in addition to the second cooling path 42b, and the cooling performance is enhanced. Since the shaft 13a of the main motor 13 is idling, the refrigerant is scattered over a wide range, and efficient cooling is possible.

Here, the state in which the refrigerant is supplied to both the first cooling passage 42a and the second cooling passage 42b is defined as the first state of the cooling performance. In the embodiment, this first state is positioned as the state having the highest cooling performance. However, the cooling performance increases or decreases depending on the ratio of the flow rates of the refrigerant supplied to the first cooling passage 42a and the second cooling passage 42b, but the ratio of the most efficient cooling performance is mainly determined. It depends on the type and specifications of the motor 13 and the configuration of the cooling means 40. Further, the refrigerant supply adjusting means 43 capable of adjusting the ratio of the flow rates of the refrigerant supplied to the first cooling passage 42a and the second cooling passage 42b only to 100: 0, 50:50, 0: 100 is adopted. In some cases. Therefore, here, the case where the refrigerant is supplied to at least both the first cooling passage 42a and the second cooling passage 42b is defined as the first state having the highest cooling performance. The first state is not limited to the state in which the cooling performance is the highest among the performances of the cooling means 40.

When the temperature of the main motor 13 drops below the second temperature threshold b while the shaft 13a of the main motor 13 idles, the temperature of the main motor 13 enters the temperature range C (see FIG. 4). When the temperature of the main motor 13 falls below the second temperature threshold value b, the main clutch 14 is switched from the disengaged state to the connected state. As shown in FIG. 2, the second temperature threshold value b is a temperature at which the temperature of the main motor 13 is lower than that of the main clutch 14 and the main clutch 14 is switched from the disconnected state to the connected state. Here, the main clutch 14 remains in the disengaged state, and the main motor 13 starts to be driven. The rotation speed of the main motor 13 is controlled so as to be maintained at the rotation speed corresponding to the vehicle speed. This is hereinafter referred to as vehicle speed tracking control. Under the vehicle speed tracking control, the cooling by the cooling means 40 shifts to the cooling condition 2. The cooling condition 2 is a cooling method in the temperature range C shown in the second stage of FIG. Under the cooling condition 2, the first cooling path discharge flag 1 and the electric motor rotation flag 1 are set, and the second cooling path discharge flag is 0. Therefore, cooling is performed only by the first cooling path 42a, and the main motor 13 is used. The shaft 13a is rotated by a driving force at a rotation speed that follows the vehicle speed. The cooling condition 2 uses only the first cooling passage 42a out of the two cooling passages 42, and the cooling performance is limited as compared with the first state using both the first cooling passage 42a and the second cooling passage 42b. It is a cooling restricted state.

The vehicle speed tracking control is performed on both sides of the main clutch 14 in the clutch disengaged state so that the recovery of the regenerative power can be started immediately by using the main motor 13 when the vehicle in the clutch disengaged state shifts to deceleration operation. It is a control that brings the rotation speeds closer to each other. When the vehicle speed tracking control is performed, the main motor 13 rotates by the driving force, so that the temperature of the main motor 13 tends to rise. However, due to the cooling of the above cooling condition 2, the temperature of the main motor 13 becomes the first. Since the temperature is maintained lower than the temperature threshold a, it is possible to prepare for the regeneration of electric power when shifting to the deceleration operation. As shown at the right end in FIG. 4, when the deceleration operation is started, the clutch is engaged and the power regeneration is started. Cooling to the main motor 13 by the cooling means 40 can be stopped until the temperature of the main motor 13 exceeds the third temperature threshold value c.

That is, in this control, as shown in FIG. 5, in the clutch disengaged state, the cooling means 40 cools, for example, in the first temperature range (corresponding to temperature ranges A and B) including a predetermined value equal to or higher than the second temperature threshold b. Condition 1 is adopted, and the refrigerant is supplied to both the first cooling passage 42a and the second cooling passage 42b to rotate the main motor 13. At this time, although the rotation of the main motor 13 is idling in the embodiment, it may be rotated by driving. Further, in the second temperature range (corresponding to the temperature range C) set to a temperature lower than the lower limit of the first temperature range (corresponding to the temperature ranges A and B), the cooling condition 2 is adopted and the first cooling path 42a is adopted. The second cooling passage 42b is cut off to stop the supply of the refrigerant, and the main motor 13 is rotated. At this time, in the embodiment, the rotation of the main motor 13 is the rotation by driving, but this may be rotated by idling. Further, in the third temperature range (corresponding to the temperature range D) set to a temperature range lower than the lower limit of the second temperature range (corresponding to the temperature range C), the cooling condition 3 is adopted, and the first cooling passage 42a and the second cooling path 42a and the second. Refrigerant is supplied to both of the cooling passages 42b to stop the rotation of the main motor 13. Further, in the fourth temperature range (corresponding to the temperature range E) set to a temperature range lower than the lower limit of the third temperature range (corresponding to the temperature range D), the cooling condition 4 is adopted to shut off the first cooling path 42a. The supply of the refrigerant is stopped and the refrigerant is supplied to the second cooling passage 42b to stop the rotation of the main motor 13.

The cooling conditions 2, 3 and 4 are all the first states having the highest cooling performance among the four cooling conditions, that is, the cooling limited state in which the cooling performance is more limited than the cooling condition 1. Further, the state in which the pump 41 is stopped, all the supply of the refrigerant is stopped, and the rotation of the main motor 13 is stopped is the minimum state of the cooling performance by the cooling means 40. That is, in this control, the cooling control means 52 sets the cooling performance to a cooling limited state in which the cooling performance is restricted more than the first state while the main clutch 14 is disengaged, and the cooling limited state is set as the temperature of the main motor 13 is higher. By controlling it so that it is close to one state, it is possible to immediately respond to the regeneration of electric power at the time of transition to the deceleration state.

As another control example, for example, the cooling control means 52 adopts a method of controlling the cooling performance by the cooling means 40 so that the higher the remaining capacity of the electric power of the battery 20 is, the closer the cooling limit state is to the first state. be able to.

FIG. 6 shows three charts (maps) based on the remaining power capacity of the battery 20. The upper row is a cooling map for high remaining capacity with high remaining power, the lower row is a cooling map for low remaining capacity with low remaining power, and the middle row is cooling for medium remaining capacity in between. Each map is shown. When the remaining capacity is high, for example, the remaining capacity of electric power can be defined as the first predetermined capacity p or more, and when the remaining capacity is low, for example, the remaining capacity of electric power can be defined as less than the second predetermined capacity r (p> r). .. At this time, when the remaining capacity is medium, it can be defined that the remaining capacity of electric power is equal to or more than the predetermined capacity r and less than the predetermined capacity p. The first predetermined capacity p can be, for example, 75% of the full charge capacity, and the second predetermined capacity r can be, for example, 25% of the full charge capacity. Here, the cooling map at the time of the remaining capacity is the same as that shown in FIG. 5, which is an example of control not based on the remaining capacity of the electric power of the battery 20.

Comparing the three maps of FIG. 6, regarding the utilization of the first cooling passage 42a, when the residual capacity is high, the refrigerant is supplied to the first cooling passage 42a under all the cooling conditions 1 to 4. When the remaining capacity is medium, the refrigerant is supplied to the first cooling passage 42a only under the cooling conditions 1 to 3, and when the remaining capacity is low, the refrigerant is supplied to the first cooling passage 42a only under the cooling conditions 1 and 2. As the remaining capacity of the amount of electricity decreases, the operating conditions for utilizing the first cooling passage 42a are reduced. This is intended to preserve the electric power remaining in the battery 20 by limiting the utilization opportunity of the first cooling passage 42a as the remaining electric power capacity is small.

Comparing the three maps shown in FIG. 6, regarding the utilization of the second cooling passage 42b, the refrigerant is not supplied to the second cooling passage 42b only under the cooling condition 3 when the remaining capacity is high. When the remaining capacity is set, the refrigerant is not supplied to the second cooling passage 42b only under the cooling condition 2, and when the remaining capacity is low, the refrigerant is not supplied to the second cooling passage 42b only under the cooling conditions 1 and 4. That is, as the remaining capacity of the electric power becomes smaller, the operating conditions for utilizing the second cooling passage 42b are reduced, and the purpose is to preserve the electric power remaining in the battery 20. However, in the case of high residual capacity, in the comparison between the cooling condition 3 and the cooling condition 4, the rotation of the main motor 13 is prioritized over the utilization of the second cooling passage 42b under the cooling condition 3 targeting a higher temperature range. In the cooling condition 4, which targets a temperature range lower than the cooling condition 3, the utilization of the second cooling passage 42b is adopted instead of the rotation of the main motor 13. Further, in the comparison between the cooling condition 2 and the cooling condition 3 at the time of the medium remaining capacity, the rotation of the main motor 13 is prioritized over the utilization of the second cooling passage 42b under the cooling condition 2 targeting a higher temperature range. In the cooling condition 3, which targets a temperature range lower than the cooling condition 2, the utilization of the second cooling passage 42b is adopted instead of the rotation of the main motor 13. Further, in the comparison between the cooling condition 1 and the cooling condition 2 at the time of low residual capacity, the rotation of the main motor 13 is prioritized over the utilization of the second cooling passage 42b under the cooling condition 1 targeting a higher temperature range. In the cooling condition 2, which targets a temperature range lower than the cooling condition 1, the utilization of the second cooling passage 42b is adopted instead of the rotation of the main motor 13. Further, under the cooling condition 4, the utilization of the second cooling passage 42b is stopped. In the embodiment, three cooling maps are set according to the remaining capacity of the battery 20, but the number of the cooling maps can be freely set. For example, two cooling maps may be set according to the remaining capacity of the battery 20, or four or more cooling maps may be set.

In the control according to each of the above aspects, the electric motor control means 53 adds a control that increases the rotation speed of the main motor 13 as the temperature of the main motor 13 increases while the main clutch 14 is disengaged. Can be done. By adding a control to increase the rotation speed of the main motor 13 as the temperature of the main motor 13 is higher, the higher the temperature of the main motor 13 is, the wider the scattering range of the refrigerant is and the higher the temperature of the main motor 13 is. The cooling performance can be improved as time goes by.

A flowchart of this control is shown in FIG. Control is started in step S1, and information on the temperature of the main motor 13 (hereinafter referred to as an electric motor in the flowchart) is acquired in step S2. In step S3, if the temperature of the electric motor is equal to or higher than the first temperature threshold value a, the main clutch 14 (hereinafter referred to as a clutch in the flowchart) is disengaged. If the temperature of the electric motor is less than the first temperature threshold value a, the process returns to the previous step and the process is repeated. The clutch is disengaged in step S4, and the temperature of the motor is acquired again in step S5. If the disengagement of the clutch is not continued in step S6, the process returns to step S2 and the process is repeated. If the clutch is continuously disengaged in step S6, the temperature of the motor is determined in step S7. Here, if the temperature of the motor is equal to or higher than the second temperature threshold value, the process proceeds to step S8 to acquire information on the remaining capacity of the battery. In the following step S9, the cooling map is selected according to the remaining capacity of the battery 20. In step S10, in the selected cooling map, the cooling of the motor is started under the cooling condition corresponding to the temperature of the motor (in this case, the cooling condition 1 is applicable). After that, the process returns to step S5 and the process is repeated. On the other hand, if the temperature of the electric motor is less than the second temperature threshold value b in step S7, the process proceeds to step S21.

In step S21, the temperature of the electric motor is determined again. Here, if the temperature of the motor is equal to or higher than the third temperature threshold value, the process proceeds to step S22 to acquire information on the remaining capacity of the battery. In the following step S23, the cooling map is selected according to the remaining capacity of the battery. In step S24, in the selected cooling map, cooling of the motor is started under the cooling condition corresponding to the temperature of the motor (in this case, the cooling condition 2 is applicable). After that, in step S25, it is determined whether or not the operating state at that time is deceleration running. The deceleration state can be determined, for example, by the speed information from the vehicle speed sensor 16, or it is estimated that the electronic control unit 50 is in the deceleration state based on the operation amount of the brake pedal 22 and the accelerator pedal 32. It is also possible. If the operating state is not decelerated traveling, the process returns to step S21 and the process is repeated. If the operating state is decelerated traveling, the process proceeds to step S26 and the clutch is engaged. Regeneration of electric power starts by connecting the clutch, and the control process ends in step S27. On the other hand, if the temperature of the motor is less than the third temperature threshold c in step S21, the process proceeds to step S31.

In step S31, the temperature of the motor is determined again. Here, if the temperature of the electric motor is equal to or higher than the fourth temperature threshold value d, the process proceeds to step S32 to acquire information on the remaining capacity of the battery. In the following step S33, the cooling map is selected according to the remaining capacity of the battery 20. In step S34, in the selected cooling map, cooling of the motor is started under the cooling condition corresponding to the temperature of the motor (in this case, the cooling condition 3 is applicable). After that, in step S35, it is determined whether or not the operating state at that time is deceleration running. If the operating state is not decelerated, the process returns to step S31 and the process is repeated. If the operating state is decelerated traveling, the process proceeds to step S36 and the clutch is engaged. Regeneration of electric power starts by connecting the clutch, and the control process ends in step S37. On the other hand, if the temperature of the motor is less than the third temperature threshold c in step S31, the process proceeds to step S42.

In step S42, information on the remaining capacity of the battery is acquired. In the following step S43, the cooling map is selected according to the remaining capacity of the battery 20. In step S44, in the selected cooling map, cooling of the motor is started under the cooling condition corresponding to the temperature of the motor (in this case, the cooling condition 4 is applicable). After that, in step S45, it is determined whether or not the operating state at that time is deceleration running. If the operating state is not decelerated running, the process returns to the previous stage and the process of step S45 is repeated. If the operating state is decelerated traveling, the process proceeds to step S46 and the clutch is engaged. Regeneration of electric power starts by connecting the clutch, and the control process ends in step S47.

In the above embodiment, the cooling passages 42 to which the refrigerant is supplied are set as two systems, and the cooling performance of the cooling means 40 is made variable by switching the cooling passages 42 of the two systems. For example, the cooling performance of the cooling means 40 may be made variable by increasing or decreasing the output of the pump 41 that sends out the refrigerant regardless of the number of systems of the cooling passage 42.

The configurations, control maps, control flow flowcharts, etc. of the hybrid vehicle 10 and its control device described in the above embodiments are merely examples for explaining the present invention, and the recovery of regenerative energy by the main motor 13 is merely an example. As long as the problem of the present invention of efficiently performing the above can be solved, the above-mentioned components, control map, control flow and the like can be appropriately changed. Further, in the above, the present invention has been described based on the vehicle 10 in which the axle direct connection type main motor 13 is provided only on the rear wheel 11b side, but the axle is different from the side where the main motor 13 is provided with the engine 12. For example, the vehicle 10 in which the main motor 13 is provided on both the front wheel 11a side and the rear wheel 11b side, and the vehicle 10 in which the main motor 13 is provided only on the front wheel 11a side. The invention can be applied.

10 Hybrid vehicle (vehicle)
11a Front wheel (wheel)
11b Rear wheel (wheel)
12 Engine 13 Motor (main motor)
14 Clutch (main clutch)
15 Temperature information acquisition means (temperature sensor)
16 Vehicle speed sensor 18 Rear wheel side axle (second drive shaft)
19 Rear wheel side differential 20 Battery 21 Charge sensor 22 Brake pedal 23 Brake sensor 24 Torque converter 25 Continuously variable transmission 26 Sub-clutch 27 Front wheel side differential 28 Front wheel side axle (first drive shaft)
29 Sub-motor (sub-motor)
30 Belt 31 Crankshaft 32 Accelerator pedal 33 Accelerator position sensor 40 Cooling means 41 Pump 42 Cooling path 42a First cooling path 42b Second cooling path 42c Return path 43 Refrigerant supply adjusting means 50 Electronic control unit 51 Clutch control means 52 Cooling control means 53 Electric motor control means 54 Control means

Claims (5)

An engine that transmits driving force to the first drive shaft,
An electric motor that transmits the driving force to the second drive shaft,
A clutch arranged between the motor and the second drive shaft,
A temperature information acquisition means for acquiring temperature information of the motor, and
A clutch control means that disengages the clutch when the temperature of the motor exceeds a predetermined value and engages the clutch when the vehicle decelerates.
A cooling means for cooling the motor and
A cooling control means for adjusting the cooling performance of the cooling means to the electric motor between the first state and the second state in which the cooling performance is lower than that of the first state.
Equipped with
The cooling control means puts the cooling performance into a cooling limited state in which the cooling performance is restricted more than the first state while the clutch is disengaged, and the cooling limited state becomes closer to the first state as the temperature of the electric motor is higher. Hybrid vehicle to control. It is equipped with a battery that supplies electric power to the motor.
The hybrid vehicle according to claim 1, wherein the cooling control means controls the cooling limit state to be closer to the first state as the remaining capacity of the electric power of the battery is higher. A motor control means for controlling the operation of the motor is provided.
The hybrid vehicle according to claim 1 or 2, wherein the motor control means controls the rotation speed of the motor to be higher as the temperature of the motor is higher while the clutch is disengaged. The cooling means supplies the first cooling passage for cooling the member on the rotating side of the electric motor, the second cooling passage for cooling the member on the fixed side of the electric motor, the first cooling passage, and the second cooling passage. The hybrid vehicle according to any one of claims 1 to 3, further comprising a refrigerant supply adjusting means for adjusting the ratio of the refrigerant to be cooled. In the first temperature range including the predetermined value, the cooling means supplies a refrigerant to the first cooling passage and the second cooling passage to rotate the electric motor.
In the second temperature range set to a temperature range lower than the lower limit of the first temperature range, the refrigerant is supplied to the first cooling path and the second cooling path is cut off to rotate the electric motor.
According to claim 4, in the third temperature range set to a temperature range lower than the lower limit of the second temperature range, the first cooling path is shut off and the refrigerant is supplied to the second cooling path to stop the motor. The hybrid vehicle described.

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